Nikki

Nicole "Nikki" she is the little sister of Ryan Jenny and big sister of Hannah and Nathan she was a baby in season 1 but a toddler in season 2 despite being a small baby she doesn't speak yet only in gibberish in season 1 she is 4 in season 2 and speaks in season 2 but she was probably 2 in season 1.

Apperances
In the some episodes, Nikki does not appear in various episodes, For example, In, Alan's happy birthday, She does not appear at all.